Semi-aromatic polyamide and low wastewater discharge preparation thereof

A semi-aromatic, low-emission technology, applied in the field of polyamide resins, can solve the problems of low solubility, high cost, and difficulty in purifying semi-aromatic polyamide salts, and achieve low active end group content, good processing stability, and improved The effect of utilization

Active Publication Date: 2009-06-24
KINGFA SCI & TECH CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Yet, there is such a problem in the prior art: when using water or alcohol as solvent to prepare semi-aromatic polyamide salt, because the solubility of aromatic dicarboxylic acid and semi-aromatic polyamide salt in these solvents is very small, Purification of semi-aromatic polyamide salt becomes very difficult, it is difficult to obtain pure semi-aromatic polyamide salt, and then the molar ratio of dicarboxylic acid and diamine cannot be accurately controlled, which affects the quality of the final product semi-aromatic polyamide. quality; when other organic solvents are used to prepare semi-aromatic polyamide salts, although high-purity semi-aromatic polyamide salts can be obtained, the cost of solvent recovery is increased
[0012] In all the above patents, there is no treatment method for the wastewater generated during the synthesis of semi-aromatic polyamides

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0051] Add 3323g (20mol) terephthalic acid, 3446g (20mol) 1,10-decanediamine, 73.27g (0.6 mol) benzoic acid, 6.85g (0.1% by weight based on the total weight of the raw materials) sodium hypophosphite, 2283g (25% by weight based on the total weight of the reaction system) waste water in Comparative Example 1, heated up after nitrogen purging. The temperature was raised to 220°C with stirring over 2 hours, the reaction mixture was stirred at 220°C for 1 hour, then the temperature of the reactants was raised to 230°C with stirring. The reaction was continued for 2 hours at a constant temperature of 230°C and a constant pressure of 2Mpa, and the pressure was kept constant by removing the formed water. After the reaction was completed, the material was discharged, and the prepolymer was vacuum-dried at 80°C for 24 hours to obtain the characteristics A prepolymer having a viscosity [η] of 0.15 dl / g. A total of 2339 g of waste water was collected during the prepolymerization, and th...

Embodiment 2

[0053] The preparation steps of Example 1 were repeated, except that the waste water added was the waste water collected in the polymerization process of Example 1. The results are shown in Table 1.

Embodiment 3

[0055] The preparation steps of Example 1 were repeated, except that the waste water added was the waste water collected in the polymerization process of Example 2. The results are shown in Table 1.

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Abstract

The invention relates to a semi-aromatic polyamide and a preparation method producing low wastewater discharge. The semi-aromatic polyamide is prepared by the following steps: adding aromatic dicarboxylic acid, aliphatic diamine containing 4-14 carbon atoms and wastewater produced in a last prepolymerization process to a pressure pan for a prepolymerization reaction; and then further performing a tackification reaction on the prepolymer to obtain the semi-aromatic polyamide. In the preparation method, the wastewater produced in the polymerization process is recycled, which greatly reduces wastewater discharge; and raw materials in the wastewater are recovered effectively, which improves the utilization ratio of the raw materials; meanwhile, the diamine in the wastewater supplements the diamine which runs off along with the water during the prepolymerization process, which ensures balance of mol ratio of monomer dicarboxylic acid and monomer diamine.

Description

technical field [0001] The invention relates to the technical field of polyamide resins, in particular to a method for preparing semi-aromatic polyamides with low waste water discharge. Background technique [0002] Aliphatic polyamides, such as PA6 and PA66, have excellent mechanical strength, heat resistance, chemical resistance, wear resistance and self-lubricating properties, and low coefficient of friction. Their applications include electronic appliances, automotive parts, furniture , building materials and fibers, has become one of the most important engineering plastics. [0003] Semi-aromatic polyamide is a polyamide resin prepared by polycondensation of diamines or dicarboxylic acids with aromatic rings and aliphatic dicarboxylic acids or diamines, and is one of the aromatic polyamides. Due to the introduction of aromatic rings into the main chain of polyamide molecules, the heat resistance and mechanical properties are improved, the water absorption rate is reduc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G69/28C08G69/26
Inventor 曹民夏世勇黄险波蔡彤旻曾祥斌
Owner KINGFA SCI & TECH CO LTD
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